He's always wanted this, of course — in 2016, after all, he audaciously proclaimed to voters during his campaign that "I alone can fix it." Now the assertion is an essential element of his defense against impeachment.

On Monday, members of Trump's legal team filed a 110-page brief outlining the arguments they will make during his Senate trial over the next few weeks. Among their claims: Trump should be acquitted of the charges because, as president, he is simply too important to be removed from office.

"Because the president himself is vested with the authority of an entire branch of the federal government, his removal would cause extraordinary disruption to the nation," Trump's lawyers wrote. The president is in charge of federal law enforcement, the military, foreign policy, and more. "His removal would necessarily create uncertainty and pose unique risks for U.S. interests around the globe."

This might be true, but it is also insufficient. And while Trump's lawyers make the case for the importance of the presidency in general terms, can anyone doubt this president in particular — with his massive-but-easily-bruised ego — truly believes that American governance will collapse if he is removed from office?

Trump makes a version of this case regularly in his tweets, often in hyperbolic terms. "We are now NUMBER ONE in the Universe, by FAR!!" he wrote Monday night as he left the country to hobnob with elites in Davos, Switzerland. And he regularly takes credit for all manner of achievements that have little or nothing to do with his leadership — a drop in cancer rates, for example, or for the opening of manufacturing plants that were operating years before he took office. If something good has happened in the country, you can be sure Trump wants you to believe he is the reason why.

But there is no such thing as an indispensable man or woman under the U.S. Constitution — nor should there be.

Yes, the presidency is important. The Founders did create a high mathematical standard for removing and replacing an official — two-thirds of the Senate must find him or her guilty of the impeachment charges. Even in less-polarized times that's a difficult standard to meet, which is why impeachment is pretty rare in U.S. history.

But the Founders also put safeguards in the Constitution against any single person — even the president — becoming too critical to governance, and this flies in the face of the argument being put forth by Trump's legal team that he is simply too important to be impeached. Notably, the Founders created the office of the vice president, which inherits the "powers and duties" of the top office if the president dies, resigns, or is removed from office. It's the American version of the "spare" in the British monarchy's "heir and a spare" formula, and so far it has worked. American vice presidents have taken over in cases of assassination, illness, and resignation. The country survived. "President Mike Pence" isn't an entirely welcome proposition, but it is insurance against the executive branch falling apart if Trump is suddenly forced from office.

More importantly, the argument by Trump's legal team for the "president's unique role in our constitutional structure" commits the sin of minimizing Congress' own constitutional role in American governance. The whole idea of "checks and balances" is, in and of itself, a counterargument to the notion of an indispensable man.

That is especially true in the case of impeachment. The Founders created this process, which is centered entirely in the House and Senate. They created it knowing the importance of the presidency within the constitutional system, and they created it knowing a successful impeachment would overturn the results of the previous presidential election. They created the impeachment process anyway.

Trump's argument against impeachment would be wrongheaded even if he was a very good president. He is not. Surely somebody else can be found who can explode the federal deficit, ruin relationships with America's allies, and start wars in the Middle East. The graveyards, they say, are full of indispensable men. No matter what he says, Trump isn't one of them.